{"id":1268,"date":"2015-11-15T21:28:16","date_gmt":"2015-11-15T21:28:16","guid":{"rendered":"http:\/\/www.sydneysmith.com\/wordpress\/?p=1268"},"modified":"2017-05-14T01:29:58","modified_gmt":"2017-05-14T01:29:58","slug":"hp67-startup-code","status":"publish","type":"post","link":"https:\/\/www.sydneysmith.com\/wordpress\/1268\/hp67-startup-code\/","title":{"rendered":"HP67 Startup code"},"content":{"rendered":"

The hp67u emulator shows a “0.00” before you get a chance to select debugging so how can you explore the HP-67’s startup code?
\n<\/p>\n

Fortunately there’s a way to start the hp67u in debug mode<\/a>. You’ll see the power switch at ON but the display is off. It looks like this:
\n\"67-debug-start\"<\/p>\n

If you tap the display (for the menu) and then select Advanced you’ll see:
\n\"67-debug-rom-00000\"<\/p>\n

It’s pretty rare to see all zeros in the internal registers and microcode step 0.<\/p>\n

From here you can turn logging on and see what happens at startup. I found it necessary to select [Step] first or the emulator starts the “Running…” process the instant you select [Log is ON] and you don’t get time to choose one of the more useful logging modes ([Log is DETAILED] or [Log is SMART]).<\/p>\n

Here’s what happens:
\n67-startup.txt<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

The hp67u emulator shows a “0.00” before you get a chance to select debugging so how can you explore the HP-67’s startup code?<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[16,5,3],"tags":[33,32],"_links":{"self":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts\/1268"}],"collection":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/comments?post=1268"}],"version-history":[{"count":2,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts\/1268\/revisions"}],"predecessor-version":[{"id":1283,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts\/1268\/revisions\/1283"}],"wp:attachment":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/media?parent=1268"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/categories?post=1268"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/tags?post=1268"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}